Japanese Patent Applications No. 2002-17651 filed on Jan. 25, 2002 and No. 2003-8067 filed on Jan. 16, 2003, are hereby incorporated by reference in their entirety.
The present invention relates to a semiconductor device which drives a display device such as a liquid crystal display device, and an electro-optical device using the semiconductor device.
An example of a conventional driver IC which drives a liquid crystal display device is described below with reference to FIG. 7. FIG. 7 shows a liquid crystal display device using a conventional driver IC. As shown in FIG. 7, a liquid crystal display device 60 includes a driver IC 20, an upper panel 30, and a substrate 40. A liquid crystal material is sealed between the substrate 40 and the upper panel 30.
The liquid crystal display device 60 has a plurality of segment regions S1, S2, . . . in a segment direction, and a plurality of common regions C1, C2, . . . in a common direction. One pixel (dot) is specified by specifying one segment region and one common region. The liquid crystal display device has 132 segment regions and 64 common regions, for example. In this case, the liquid crystal display device has 132xc3x9764 pixels. The driver IC 20 is generally mounted on the substrate 40 so that the side of the driver IC 20 on which terminals are formed (active side) faces the substrate 40. The terminals are connected with interconnects of the substrate 40.
The driver IC 20 supplies segment signals to a plurality of the segment regions. The driver IC 20 supplies common signals to a plurality of the common regions. The driver IC 20 has a shape which is long in one direction. Segment signal output terminals QS1 to QS132 for outputting the segment signals are formed along one side in the longitudinal direction of the mounting side of the driver IC 20 (upper long side in FIG. 7). Common signal output terminals QC1 to QC32 and QC33 to QC64 for outputting the common signals are formed along two sides which intersect the longitudinal direction of the mounting side of the driver IC 20 at right angles (left and right short sides in FIG. 7). Input/output terminals QT1 to QTn are formed along the other side in the longitudinal direction of the mounting side of the driver IC 20 (lower long side in FIG. 7).
Transparent segment interconnects LS1 to LS132 and common interconnects LC1 to LC64 are formed on the substrate 40. One end of each of the segment interconnects LS1 to LS132 is connected with one of the segment regions S1 to S132 of the liquid crystal display device. The other end of each of the segment interconnects LS1 to LS132 makes up an electrode for connecting the segment signal output terminals QS1 to QS132 of the driver IC 20. Similarly, one end of each of the common interconnects LC1 to LC64 on the substrate 40 is connected with one of the common regions C1 to C64 of the liquid crystal display device. The other end of each of the common interconnects LC1 to LC64 makes up an electrode for connecting the common signal output terminals QC1 to QC64 of the driver IC 20. The common electrodes on the upper panel 30 are electrically connected with the common interconnects LC1 to LC64 on the substrate 40 through a conductive bead, silver paste, or the like (not shown in FIG. 7). In other words, the common electrodes on the upper panel 30 are electrically connected with the common output terminals of the driver IC 20 through the common interconnects on the substrate 40.
In the above-described conventional driver IC, the pitch and size of the segment signal output terminals and the common signal output terminals are the same. However, when mounting such a driver IC on the substrate, the common signal output terminals formed on both ends of the longitudinal direction of the driver IC are significantly affected by an assumed error of the installation angle of the driver IC in addition to an assumed alignment error in the longitudinal direction and an assumed alignment error in the direction of the short side, whereby alignment allowance is reduced.
Reduction of alignment allowance results in a decrease in a substantial junction area between the terminal and the interconnect of the substrate when misalignment occurs, whereby problems relating to mounting reliability such as deterioration of electrical characteristics due to an increase in electrical resistance in the junction region and a decrease in strength of the connection area between the terminal and the interconnect of the substrate tend to occur.
Japanese Patent Application Laid-open No. 5-63022 and Japanese Patent Application Laid-open No. 9-24635 disclose ICs for driving a head in which output terminals for a head drive signal are disposed near the upper side of a driver IC, input terminals for a clock signal, data signal, and latch signal are disposed near the left side, output terminals for the clock signal, data signal, and latch signal are disposed near the right side, and input terminals for remaining signals are disposed near of the lower side. The pitch of the input terminals near the left side of the driver IC and the pitch of the output terminals near the right side of the driver IC are greater than the pitch of the output terminals near the upper side. However, if the pitch of the terminals near the left side and the right side is increased, the area of the substrate of the driver IC is increased, whereby a high degree of integration cannot be achieved.
Japanese Patent Application Laid-open No. 9-68715 discloses a liquid crystal display device in which dummy bumps which do not take part in electrical connection are provided in order to reduce occurrence of inclination or misalignment caused by nonuniformity of arrangement density of the bumps when mounting the driver IC.
The present invention may provide a semiconductor device having terminals which can be connected with high reliability, and an electro-optical device including the same.
One aspect of the present invention relates to a semiconductor device for supplying a signal to an electro-optical device which displays a two-dimensional image, the semiconductor device including:
first terminals which are formed along a first side of the semiconductor device in a longitudinal direction and have a length L1 in a direction intersecting the longitudinal direction at right angles; and
second terminals which are formed along a second side intersecting the first side at right angles and have a length L2 which is greater than the length L1 in the longitudinal direction.
Another aspect of the present invention relates to an electro-optical device having an electro-optical material layer, the electro-optical device comprising:
the semiconductor device as defined in any one of claims 1 to 10 provided over a substrate,
wherein the first terminals include output terminals for supplying a signal to first electrodes, and
wherein the second terminals include output terminals for supplying a signal to second electrodes which intersect the first electrodes.